1. Field of the Invention
The present invention relates to a photosensitive belt cartridge which receives, in a continuous loop belt state, the photosensitive belt installed in an electrophotographic printer for convenience of replacement and safe storage thereof, and a photosensitive belt replacing apparatus employing the same and a method thereof.
2. Description of the Related Art
An electrophotographic printer such as a color laser printer is provided with a photosensitive belt 10 supported by and circulating around a plurality of rollers 11, 12 and 13 installed in a main body of the printer as shown in FIG. 1. An image to be printed is developed on a surface of the photosensitive belt 10 by a predetermined developing unit 15, and after the developed image is dried while passing through a drying unit 16, the image is printed on a paper 1 at a transfer unit 14 including a transfer roller 14a and a fuser roller 14b.
Here, a unit in which the photosensitive belt 10 circulates is called a belt unit. In addition, the roller 11 of the rollers 11, 12 and 13 is a drive roller which is connected to a driving source and circulates the photosensitive belt 10, the roller 12 is a backup roller for the transfer roller 14a, and the roller 13 acts as a steering roller for preventing lateral movement of the photosensitive belt 10.
However, as such a photosensitive belt is used for a long time, the precision of a developed image deteriorates gradually. Therefore, when a predetermined use life has passed, the photosensitive belt must be replaced with a new one so as to continuously develop a clear image. However, in a conventional method for such replacement, a photosensitive belt formed as a continuous loop belt as mentioned above is replaced with a new one in a manner in which the photosensitive belt is adjusted to an installment position in the main body and inserted into the position directly by hand. To this end, one of the rollers 11, 12 and 13, that is, the steering roller 13 is installed to be movable as shown by an imaginary line in FIG. 1, the steering roller 13 is moved to a position shown by the imaginary line to loosen the tension of the photosensitive belt 10 during replacement, and then the photosensitive belt 10 is removed. Thereafter, the new photosensitive belt is inserted by hand, and then the steering roller 13 is moved to the original position to tighten the tension of the photosensitive belt 10.
However, since the photosensitive belt 10 has no rigid shape and is flexible, it is very troublesome and difficult in itself to replace the photosensitive belt 10 with a new one by adjusting the photosensitive belt 10 to the installation position and inserting it into the position by hand, and in addition there is a problem in that the possibility of improper installation of the new photosensitive belt may be high depending on the worker performing the replacement job. In addition, since the worker must put his hand into the printer, hold the photosensitive belt 10 and pull it out directly by hand when the photosensitive belt 10 is removed from the printer, the hand of the worker may be injured by interference with various structural members in the tight inner space of the printer.